DESCRIPTION (Verbatim from Applicant's Abstract): Group B streptococcus (GBS, Streptococcus agalactiae) is the most common cause of neonatal sepsis and meningitis in the USA. A humoral factor has been discovered in normal mouse serum which protects the animals against GBS infection. It is hypothesized that the protective factor is natural IgM antibody. Two goals of the proposed research are: (i) To confirm that the antibody is of the IgM type and that it is protective against experimental GBS infections in vivo; (ii) to identify the antigenic target for this antibody on the bacterial surface. To these aims, several clinical isolates and mutant strains of GBS, in combination with in vitro enzyme-linked immunosorbent assays (ELISA) and in vivo mouse protection experiments will be utilized. Results obtained with mice as animal model may open a new avenue of investigation into possible role of natural antibodies in human immunity to GBS infection and bacterial infection in general, with possible implications for immunotherapy. The results also may provide impetus to the research on the antigenic targets on GBS, possibly other than the capsular polysaccharide, which would have implications for current GBS vaccine efforts. A non-scientific goal of this project is to increase the intensity of health-related undergraduate research and teaching in a mid-size rural university with no medical school and to increase diversity in the work force in the academic research and medicine.